Equivalent Strength for Tunnels in Cement-Admixed Soil Columns with Spatial Variability and Positioning Error
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 146, Issue 10
Abstract
Cement-admixed soil columns are often used to strengthen the surrounding soft soil for enhancing tunnel stability. Such improved soil surrounds possess high spatial variability and heterogeneity in the strength and stiffness properties. In this paper, three-dimensional random finite-element analysis is conducted to compute the equivalent strength and stiffness for tunnels constructed in overlapping cement-admixed soil columns surrounded by soft clays. The heterogeneity and spatial variability of the improved soil surround are studied by varying coefficient of variation, considering anisotropic scale of fluctuation in mean strength and stiffness, as well as varying positioning error arising due to the off-verticality in cement-treated columns. Finally, strength reduction factors are computed for obtaining the equivalent strength of tunnels in such spatially variable improved soils. The proposed range of strength reduction factors can be used in numerical analysis by engineers in practice to compute the appropriate values of equivalent strength and stiffness of homogeneous improved soil surrounds around tunnels. The influence of varying permeability of improved soil surround and time of excavation of tunnel opening on the equivalent strength is also studied and was not found to be significant.
Get full access to this article
View all available purchase options and get full access to this article.
Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
This research is supported by the National Research Foundation Singapore under its Competitive Research Programme (CRP award No. NRF-CRP 6-2010-03) and the NUS Research Scholarship.
References
Ali, A., A. V. Lyamin, J. Huang, S. W. Sloan, and M. J. Cassidy. 2017. “Undrained stability of a single circular tunnel in spatially variable soil subjected to surcharge loading.” Comput. Geotech. 84 (Apr): 16–27. https://doi.org/10.1016/j.compgeo.2016.11.013.
Broms, B. B. 2004. “Lime and lime/cement columns.” In Vol. 2 of Ground improvement, edited by M. P. Moseley and K. Kirsch, 252–330. London: Taylor & Francis.
Broms, B. B., and H. Bennermark. 1967. “Stability of vertical openings in clays.” J. Soil Mech. Found. Div. 93 (1): 71–94.
Canetta, G., B. Cavagna, and R. Nova. 1996. “Experimental and numerical tests on the excavation of railway tunnel in grouted soil in Milan.” In Geotechnical aspects of underground construction in soft ground, edited by R. J. Mair and R. N. Taylor, 479–484. Rotterdam, Netherlands: A.A. Balkema.
Casarin, C., and R. J. Mair. 1981. “The assessment of tunnel stability in clay by model tests.” In Soft ground tunnelling, failures and displacements, 33–44, edited by D. Resendiz and M. Romo. Rotterdam, Netherlands: A.A. Balkema.
CEN (European Committee for Standardization). 2002. Eurocode—Basis of structural design. BS EN 1990. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2004. Eurocode—Geotechnical design. Part 1: General rules. BS EN 1997-1. Brussels, Belgium: CEN.
Chen, J., F. H. Lee, and C. C. Ng. 2011. “Statistical analysis for strength variation of deep mixing columns in Singapore.” In Proc., Geo-Frontiers 2011: Advances in Geotechnical Engineering, edited by J. Han and D. E. Alzamora, 576–584. Reston, VA: ASCE.
Chin, K. G. 2006. “Constitutive behaviour of cement treated marine clay.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, National Univ. of Singapore.
Chong, T., K. K. Phoon, and A. H. Soubra. 2013. “Stability analysis of a pressurized tunnel face in a spatially varying sand using the statistical approach of limit analysis.” In Safety, reliability, risk and life-cycle performance of structures & infrastructures, edited by G. Deodatis, B. R. Ellingwood, and D. M. Frangopol. London: Taylor & Francis.
Coulter, S., and C. D. Martin. 2004. “Ground deformations above a large shallow tunnel excavated using jet grouting.” In Proc., ISRM Regional Symp., EUROCK 2004 and 53rd Geomechanics Colloquy, edited by W. Schubert, 155–160. Essen, Germany: VGE Verlag.
Dames and Moore. 1983. Singapore mass rapid transit system—Detailed geotechnical study interpretative report. Singapore: Provisional Mass Rapid Transit Authority.
Davis, E. N., M. J. Gunn, R. J. Mair, and H. N. Seneviratne. 1980. “The stability of shallow tunnels and underground openings in cohesive material.” Géotechnique 30 (4): 397–416. https://doi.org/10.1680/geot.1980.30.4.397.
Dempsey, A., and K. Moller. 1970. Grouting in ground engineering. London: Institution of Civil Engineers.
González-Nicieza, C., A. E. Álvarez-Vigil, A. Menéndez-Díaz, and C. González-Palacio. 2008. “Influence of the depth and shape of a tunnel in the application of the convergence–confinement method.” Tunnelling Underground Space Technol. 23 (1): 25–37. https://doi.org/10.1016/j.tust.2006.12.001.
Ho, J. 2013. “Cyclic and post cyclic behavior of soft clays.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, National Univ. of Singapore.
Honjo, Y. 1982. “A probabilistic approach to evaluate shear strength of heterogeneous stabilized ground by deep mixing method.” Soils Found. 22 (1): 23–38. https://doi.org/10.3208/sandf1972.22.23.
Kamruzzaman, A. H. M. 2003. “Physico-chemical and engineering behaviour of cement treated Singapore marine clay.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, National Univ. of Singapore.
Kawasaki, T., S. Saitoh, Y. Suzuki, and R. Babasaki. 1984. “Deep mixing method using cement slurry as hardening agent.” In Proc., Seminar on Soil Improvement and Construction Techniques in Soft Ground, 17–38. Singapore: Nanyang Technological Univ.
Kimpritis, T., W. Smon, P. Pandrea, and G. Vukotic. 2014. “Jet grouting—A solution to problems in tunneling. Examples from Europe.” In Proc., 2nd Eastern European Tunnelling Conf., 1–10. Athens, Greece: Greek Tunnelling Society.
Lambe, T. W., and R. V. Whitman. 1969. Soil mechanics. New York: Wiley.
Larsson, S. 2001. “Binder distribution in lime-cement columns.” Ground Improv. 5 (3): 111–122. https://doi.org/10.1680/grim.2001.5.3.111.
Larsson, S., and A. Nilsson. 2009. “Horizontal strength variability in lime-cement columns—A field study.” In Proc., Int. Symp. on Deep Mixing and Admixture Stabilization, edited by M. Kitazume. Okinawa, Japan: Port and Airport Report Institute.
Larsson, S., H. Stille, and L. Olsson. 2005. “On horizontal variability in lime-cement columns in deep mixing.” Géotechnique 55 (1): 33–44. https://doi.org/10.1680/geot.2005.55.1.33.
Leca, E., and L. Dormieux. 1990. “Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material.” Géotechnique 40 (4): 581–606. https://doi.org/10.1680/geot.1990.40.4.581.
Lee, C. J., B. R. Wu, H. T. Chen, and K. H. Chiang. 2006. “Tunnel stability and arching effects during tunneling in soft clayey soil.” Tunnelling Underground Space Technol. 21 (2): 119–132. https://doi.org/10.1016/j.tust.2005.06.003.
Lee, Y., I. Yogarajah, and F. H. Lee. 1998. “Engineering properties of grouted marine clay.” In Proc., 2nd Int. Conf. on Ground Improvement Techniques. Singapore: CI-Premier Conference Organisation.
Liu, Y., L. Q. He, Y. J. Jiang, M. M. Sun, E. J. Chen, and F. H. Lee. 2019. “Effect of in situ water content variation on the spatial variation of strength of deep cement-mixed clay.” Géotechnique 69 (5): 391–405. https://doi.org/10.1680/jgeot.17.P.149.
Liu, Y., Y. Jiang, H. Xiao, and F. H. Lee. 2017. “Determination of representative strength of deep cement-mixed clay from core strength data.” Géotechnique 67 (4): 350–364. https://doi.org/10.1680/jgeot.16.P.105.
Liu, Y., F. H. Lee, S. T. Quek, and M. Beer. 2014. “Modified linear estimation method for generating multi-dimensional multivariate Gaussian field in modelling material properties.” Probab. Eng. Mech. 38 (Oct): 42–53. https://doi.org/10.1016/j.probengmech.2014.09.001.
Liu, Y., F. H. Lee, S. T. Quek, J. E. Chen, and J. T. Yi. 2015. “Effect of spatial variation of strength and modulus on the lateral compression response of cement-admixed clay slab.” Géotechnique 65 (10): 851–865. https://doi.org/10.1680/jgeot.14.P.254.
Mair, R. J. 1979. “Centrifugal modelling of tunnel construction in soft clay.” Ph.D. thesis, Dept. of Engineering, Univ. of Cambridge.
Mollon, G., D. Dias, and A. H. Soubra. 2009. “Face stability analysis of circular tunnels driven by a pressurized shield.” J. Geotech. Geoenviron. Eng. 136 (1): 215–229. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000194.
Mollon, G., K. K. Phoon, D. Dias, and A.-H. Soubra. 2011. “Validation of a new 2D failure mechanism for the stability analysis of a pressurized tunnel face in a spatially varying sand.” J. Eng. Mech. 137 (1): 8–21. https://doi.org/10.1061/(ASCE)EM.1943-7889.0000196.
Namikawa, T., and J. Koseki. 2013. “Effects of spatial correlation on compression behavior of cement-treated column.” J. Geotech. Geoenviron. Eng. 139 (8): 1346–1359. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000850.
Navin, M. P. 2005. “Stability of embankments founded on soft soil improved with deep-mixing-methodcolumns.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, Virginia Polytechnic Institute and State Univ.
O’Rourke, T. D., and A. J. McGinn. 2006. “Lessons learned for ground movements and soil stabilization from the Boston Central Artery.” J. Geotech. Geoenviron. Eng. 132 (8): 966–989. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:8(966).
Paiboon, J. 2013. “Numerical analysis of homogenization using random finite element method.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, Colorado School of Mines.
Paiboon, J., D. V. Griffiths, J. Huang, and G. A. Fenton. 2013. “Numerical analysis of effective elastic properties of geomaterials containing voids using 3D random fields and finite elements.” Int. J. Solids Struct. 50 (20–21): 3233–3241. https://doi.org/10.1016/j.ijsolstr.2013.05.031.
Pan, Y., F. H. Lee, Y. Liu, and H. Xiao. 2016. “Effect of spatial variability on undrained triaxial test of cement-admixed soil.” In Vol. 2 of Proc., 15th Asian Regional Conf. on Soil Mechanics and Geotechnical Engineering, 2101–2106. Tokyo: Japanese Geotechnical Society.
Pan, Y., Y. Liu, A. Tyagi, F. H. Lee, and D. Q. Li. 2020. “Model-independent strength-reduction factor for effect of spatial variability on tunnel with improved soil surrounds.” Géotechnique 1–17. https://doi.org/10.1680/jgeot.19.P.056.
Pan, Y., Y. Liu, H. Xiao, F. H. Lee, and K. K. Phoon. 2018. “Effect of spatial variability on short- and long-term behaviour of axially-loaded cement-admixed marine clay column.” Comput. Geotech. 94 (Feb): 150–168. https://doi.org/10.1016/j.compgeo.2017.09.006.
Pellegrino, G., and D. A. Bruce. 1996. “Jet grouting for the solution of tunneling problems in soft clays.” In Grouting and deep mixing, edited by R. Yonekura, M. Terashi, and M. Shibazald, 347–352. Rotterdam, Netherlands: A.A. Balkema.
Porbaha, A., J.-L. Raybaut, and P. Nicholson. 2001. “State of the art in construction aspects of deep mixing technology.” Ground Improv. 5 (3): 123–140. https://doi.org/10.1680/grim.2001.5.3.123.
Sariosseiri, F., and B. Muhunthan. 2009. “Effect of cement treatment on geotechnical properties of some Washington State Soils.” Eng. Geol. 104 (1–2): 119–125. https://doi.org/10.1016/j.enggeo.2008.09.003.
Shen, S. L., J. Han, and Y. J. Du. 2008. “Deep mixing induced property changes in surrounding sensitive marine clays.” J. Geotech. Geoenviron. Eng. 134 (6): 845–854. https://doi.org/10.1061/(ASCE)1090-0241(2008)134:6(845).
Shen, S. L., Z. F. Wang, J. Yang, and C. E. Ho. 2013. “Generalized approach for prediction of jet grout column diameter.” J. Geotech. Geoenviron. Eng. 139 (12): 2060–2069. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000932.
Singapore Standard. 2003. Code of practice for foundations. Singapore: Spring Singapore.
Sloan, A. W., and A. Assadi. 1993. “Stability of shallow tunnels in soft ground.” In Predictive Soil Mechanics: Proc., Wroth Memorial Symp., 644–663. London: Thomas Thelford.
Tan, T. S., T. L. Goh, and K. Y. Yong. 2002. “Properties of Singapore marine clays improved by cement mixing.” Geotech. Test. J. 25 (4): 422–433. https://doi.org/10.1520/GTJ11295J.
Teo, H. J. 2017. “1-G modelling of wet deep mixing with fibres.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, National Univ. of Singapore.
Tyagi, A., and F. H. Lee. 2017. “Factors affecting the stability of large diameter tunnel in improved soil surround.” In Proc., 19th Int. Conf. on Soil Mechanics and Geotechnical Engineering 2017, edited by W. Lee, J.-S. Lee, H.-K. Kim, and D.-S. Kim, 1785–1788. Seoul: Korean Geotechnical Society.
Tyagi, A., Y. Liu, Y. T. Pan, K. B. M. Ridhwan, and F. H. Lee. 2018. “Stability of tunnels in cement-admixed soft soils with spatial variability.” J. Geotech. Geoenviron. Eng. 144 (12): 06018012. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001988.
Tyagi, A., M. F. B. Zulkefli, Y. Pan, S. H. Goh, and F. H. Lee. 2017. “Failure modes of tunnels with improved soil surrounds.” J. Geotech. Geoenviron. Eng. 143 (11): 04017088. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001788.
Wu, B. R., and C. J. Lee. 2003. “Ground movements and collapse mechanisms induced by tunneling in clayey soil.” Int. J. Phys. Modell. Geotech. 3 (4): 15–29. https://doi.org/10.1680/ijpmg.2003.030402.
Xiao, H., F. H. Lee, and Y. Liu. 2017. “Bounding surface cam-clay model with the cohesion for cement-admixed clay.” Int. J. Geomech. 17 (1): 04016026. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000671.
Xiao, H. W. 2009. “Yielding and failure of cement treated soil.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, National Univ. of Singapore.
Yeo, C. H. 2011. “Stability and collapse mechanisms of unreinforced and forepole-reinforced tunnel headings.” Ph.D. thesis, Dept. of Civil and Environmental Engineering, National Univ. of Singapore.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 146 • Issue 10 • October 2020
Copyright
© 2020 American Society of Civil Engineers.
History
Received: Oct 30, 2019
Accepted: May 19, 2020
Published online: Jul 21, 2020
Published in print: Oct 1, 2020
Discussion open until: Dec 21, 2020
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.